Hi, On Tue, Aug 24, 2010 at 08:54:58AM -0500, Matthew Schlegel wrote: > Howdy, > > > > I am working on setting up a farm of mysql servers using > heartbeat/pacemaker to control failover and resource location. Each > particular mysql server is independent, and when resources are > available, it should run on a server that isn't doing anything else for > best performance. Is there a simple way to express something along the > lines of 'Only run one resource group per node when possible'? Ideally > this same mechanism can be used to balance the number of resource groups > running on a single node as well. > > > > Currently the environment has 4 nodes and 4 mysql resource groups. The > design allows for both the resource group & node count to grow > independently as needed. > > > > I was able to get the expected collocation behavior using a collocation > rule with a negative score, however, it looks like I would need a full > matrix of these collocation rules between every resource group, and both > directions are needed. I tried doing a 'from group to any' rule, but > that didn't have any effect. > > > > I could also use location constraints to have resource groups prefer a > specific node as its 'home', however, that runs the risk of a failure > causing a single node to take the load of any resources running on the > failed node, instead of spreading that load out.
Pacemaker will try to balance the number of resources running on each node. Not perfect, but there's a good chance that no single node will run all the resources as you suggest. I think that doing location preferences is the right way to deal with this: location l-mysql1 mysql1 100: node1 etc If node1 fails, mysql1 would move elsewhere. If the mysql1 fails, then you can use migration-threshold to control how many times to try to restart it. Use resource-stickiness to control when resources fail back. Finally, how often do you expect your resources/nodes to fail? Thanks, Dejan > Is there a simple way to build this type of behavior? > > > > Thank you, > > > > > > Matthew Schlegel > > System Analyst > > > > eXcellence in IS Solutions, Inc. (X-ISS) > > Office: 713.862.9200 x203 > > http://www.x-iss.com <http://www.x-iss.com> > > > > Making IT Work for You > HPC & Enterprise IT Solutions > > > > > > > NOTICE: > This message may contain privileged or otherwise confidential information. > If you are not the intended recipient, please immediately advise the sender > by reply email and delete the message and any attachments without using, > copying or disclosing the contents. > > > _______________________________________________ > Pacemaker mailing list: [email protected] > http://oss.clusterlabs.org/mailman/listinfo/pacemaker > > Project Home: http://www.clusterlabs.org > Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf > Bugs: > http://developerbugs.linux-foundation.org/enter_bug.cgi?product=Pacemaker _______________________________________________ Pacemaker mailing list: [email protected] http://oss.clusterlabs.org/mailman/listinfo/pacemaker Project Home: http://www.clusterlabs.org Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf Bugs: http://developerbugs.linux-foundation.org/enter_bug.cgi?product=Pacemaker
